Advanced Materials Research Vols. 706-708

Abstract: This paper focus on the water distribution of secondary cooling for beam blank continuous casting process. Analysis of the influencing factors and initial determination method for important parameters of secondary cooling water, including specific water, water ratio in each secondary cooling zoon and the amount of water in outer arc, inner arc and sider at one secondary cooling zoon. After that, according to the simulation heat transfer process of the secondary cooling, to improve the secondary cooling system is given. This work provides a reference to the development of secondary cooling system.

Abstract: We developed reciprocating cutter, then use software ADAMS to optimize and improve it. The output of simulation shows that the cutter performance is good, while vibration problem exists at the same time.

Abstract: In this study a fold-type board collector in air-heating is introduced. The factor of fold-type board collector angle action that contributes to the temperature and velocity field were respectively discussed. Numerical simulation of the thermal properties of fold-type collector on different angle with Fluent software. Numeric simulation calculations shown: the fold-type board collector angle action has a greater influence for the thermal properties of collector in air-heating ,the thermal efficiency when is 30°is better than is 45°and is 60°and under this work simulation condition the optimum angle for folded-type panel air collector will be recommend nearby at =30°.

Abstract: The stiffness characteristics of a rotating cracked shaft including elliptical front edge between transverse crack and 45° slant crack have been studied here. The strain energy release rate (SERR) method has been used to calculate the stiffness matrix of two types of the crack element. Time-varying characteristics of stiffness of the straight front edge and elliptical front edge of the cracked shaft were studied in a stable rotation cycle. The analytical result of this paper shows that change of the cracked shaft stiffness raises during the increase of the crack depth. The stiffness characteristics of the rotor with slant crack having elliptical front edge vary differently from those of the rotor with transverse crack having elliptical front edge.

Abstract: In order to systematically study the CNC machine tools panel appearance of various factors on the operating efficiency, on the basis of theoretical research in cognitive psychology, ergonomics and other design principles put forward the manmachine interface for CNC machine tools equipment operating efficiency and apply it to the improved design of the CNC machine tools panel formed for the panel color key position, key symbols single factor and combination of factors and improved design to reduce the error of CNC machine tools in operation, reduce operator fatigue and psychological discomfort, allowing more perfect, more practical CNC machine tools.

Abstract: Since the transmission corridors are becoming more and more valuable and the demand for transmission capacity is continually increasing, the four-circuit transmission lines on the same tower have been used more and more in the high-voltage system. For this complex transmission system, there is an unpredictable mutual inductance error when measures the impedance, which will potentially cause the mal-operation of relay. Therefore, it is not feasible to use the traditional earth-fault distance protection in case of the single phase to earth fault. In this paper, twelve-sequence components method is introduced to decouple mutual electromagnetic effect between four-parallel transmission lines. Based on the analysis of the features of each component, the relationship between fault voltage and the current is presented. Furthermore, a new protection criterion for earth-fault distance protection is proposed. The new method has high sensitivity and reliability under different scenarios.

Abstract: Now MPM mill is widely used in hydraulic servo control technology in the field of seamless steel pipe production. But the hydraulic control system has the defect of complex control, bigger load power, more disturbance factors, higher response speed requirement and so on, which are unfavorable for analyzing the impact of factors of steel rolling precision. The conclusions show that: the system model is conducive to the analysis of the factors that affect the rolling accuracy, and it provides a theoretical basis for study the dynamic characteristics of the system, the optimal design and so on.

Abstract: Underbalanced drilling is a new method for the exploratory development of low pressure and permeability reservoirs; circulative micro-foam drilling fluid is a new technology which is developed for realizing near-balanced drilling and underbalanced drilling. The flow behavior of circulative micro-foam drilling fluid in wellbore was researched by applying HPHT experiment apparatus. It is concluded that the flow behavior parameters of circulative micro-foam drilling fluid is only related to temperature but not to pressure; the constitutive equation accords with the rheological law of power-law fluid, the expressions of consistency coefficient and liquidity index were obtained through analyzing the flow behavior experiment data under the condition of HTHP. The density of circulative micro-foam drilling fluid increases as the increase of pressure and decreases as the increase of temperature, but in wellbore the rate of increase as pressure is greater than that of decrease as temperature, so the density of drilling fluid in wellbore is greater than that under ground condition. The fluid drag force of micro-foam drilling fluid in annulus were analyzed theoretically and the pressure distribution formulas of micro-foam drilling fluid in wellbore were given.

Abstract: Air jet researchers want to improve the air jets (curtain) ability of cutting off heat exchange, dust and toxic substance diffusion. It is a natural idea to enhance the effect by two air jet flow. The motion model of the two jet flow is very complex and the final vibration mode corresponding to the different can smoke effect his paper designs a generator of two jet air. Acquiring the form, qualitative rules and the influence law of the two jet of eddy that the structure generates and simulates the vortex multi-scale simulation by FDS (Fire Dynamic Simulator) software, the quantitative relation based on the model and jet flow parameters. The law and the quantitative relationship could be used for fire safety designers.

Abstract: The mechanism model of vibration compaction system was built. The vibration friction mechanism of vibratory compaction system was studied based on granular dynamics theory. The results show that the void ratio does a great impact on strength and compaction.